Graphene is a two-dimensional (2D) structure of carbon atoms with unique electronic, chemical, and mechanical properties [1-5]. Extensive research has shown the potential of graphene or graphene-based sheets to impact a wide range of technologies including energy storage [6-10], catalysis [11-12], sensing [13-15], and composites [16-20]. Developing three-dimensional (3D) structures with this extraordinary nanomaterial would further expand its significance both in the number of applications and in the manufacturability of devices. However, literature on the assembly of 3D graphene structures is limited [12, 20-24]. Typically, previous reports relied on the high stability of graphene oxide (GO) suspensions to assemble an initial GO macrostructure, which is then thermally reduced to yield the 3D graphene network. These reports indicated that physical crosslinks (e.g. Van der Waals forces) hold the 3D graphene networks together and, as a result, bulk electrical conductivities of these assemblies only reach approximately 5×10−1 S/m [23]. Even when metal crosslinks are used between graphene sheets instead of weak physical bonds, electrical conductivities of only 2.5×10−1 S/m were reached [12]. These numbers are several orders of magnitude below the conductivity reported for graphene sheets (about 8×103 S/m) produced by thermal reduction of GO [25]. Clearly, a need exists to improve 3D graphene macroassemblies.